Thousands of different products are packaged in some kind of plastic container. The food industry uses them for such items as frozen pizza, frozen vegetables and fountain soda. The medical industry uses plastic bags for IV solutions and blood among others. In some cases a failed seal may affect the shelf life of the product or allow contaminants to enter. In another case, such as holding laundry detergent tablets, a failed seal is just a nuisance for the user. In any case, a failed seal ultimately reflects on the quality image of the supplier which may lead to a decline in future sales.
For some applications product is being sealed inside, while for others the product is the specialty plastic bag. Whether sealing in the final product or just making seals to create a bag, the process is similar. The product is indexed along the process line where it enters a heating press. The press is clamped on the areas to be sealed and then heat is applied until the plastic components are fused together. Heat is removed to start the cooling cycle before the press is released. The cycle repeats with the next part being indexed into position. Manufacturers run the cycle as quickly as possible to maximize production yield, but unfortunately the seal defects increase as the cycle speed is increased.
A thermal imaging system may function both as a tool to increase the cycle speed and also as an automatic fault detection system.
While the method and device described herein are susceptible to various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the disclosure and the appended claims.